Kerala State Board New Syllabus Plus Two Zoology Chapter Wise Previous Questions and Answers Chapter 7 Microbes in Human Welfare.
Kerala Plus Two Zoology Chapter Wise Previous Questions Chapter 7 Microbes in Human Welfare
Question 1.
Ramu cultivated pea plants as an intercrop in his paddy field. After harvesting, he allowed the roots of the pea plants remain in the soil for some period. (MARCH-2010)
a) Do you think the action of Ramu is reasonable?
b) Justify your answer.
Answer:
Yes.
Rhizohium found in the root nodules in the pea plant can fix atmospheric nitrogen into nitrates and in-creases fertility of soil.
Question 2.
Match column I with II. (MAY-2010)
| Column I | Column II |
| 1. Methano bacteria | 1. Plague |
| 2. Bacillusthuringenesis | 2. Cyclosporin A |
| 3. Azo Spirillum | 3. Gobar gas production |
| 4. Trichoderma poly | 4. Bio Control sporum |
| 5. Citric acid production | |
| 6. Bio fertilizer |
Answer:
| Column I | Column II |
| 1. Methano bacteria | 1. Gobar gas production |
| 2. Bacillus thuringenesis | 2. Bio Control |
| 3. Azo Spirillum | 3. Bio fertilizer |
| 4. Trichoderma | 4. Cyclosporin A poly sporum |
Question 3.
A bacterial infection was effectively controlled by using a specific anitibiotic for a long time. But nowadays this antibiotic is not found to be so effective to control the said infection. (MARCH-2011)
Give a scientific explanation for this phenomenon based on evolution.
Answer:
Evidence for Natural selection and explanations like origin of antibiotic resistant varieties or elimination of sensitive varieties or Natural selection by Anthropo-genic action.
Question 4.
Rearrange the columns B & C with respect to A. (MARCH-2012)
| A | B | C |
| Monascus
purpureus |
Streptokinase | Antibiotic |
| Streptococcus | Statin | Immuno
suppressant |
| Penicillium
notatum |
Cyclosporin-A | Clot buster |
| Trichoderma
polysporum |
Penicillin | Cholesterol
lowering agent |
Answer:
Monascus – Statin – Cholesterol
Streptococcus – Streptokinase – Cholestrol lowering
Pencillium – Penicillin – Antibiotic
Trichoderma – Cyclosporin-A – Immuno suppressant
Question 5.
Match the following (MAY-2012)
Answer:
(A) – (3)
(B) – (2)
(C) – (1)
(D) – (5)
Question 6.
Some bioactive molecules, their source and their medical impotance are given in the table below. Fill up the missing parts. (MARCH-2013)
| Bioactive molecule | Source | Medical importance |
| a | streptococcus | Removes clots from blood vessels |
| Cyclosporin A | b | c |
| d | Monascus purpureus | Blood cholesterol lowering agent |
Answer:
a) streptokinase
b) Trichoderma polysporum
c) Immunosuppressant in organ transplant patients
d) Statins
Question 7.
Complete the illustration appropriately. (MAY-2013)
Answer:
a) Biofertilisers
b) Yeast,ethanol production,
c) (1) Lady bird and dragon flies are useful in the elimination of aphids and mosquitoes.
(2) Bacillus thuringiencis
d) Dough for making dosa and idly is fermented by Bacteria.
Question 8.
The meaning of ‘antibiotics’is ‘against life’, whereas with reference to human beings they are ‘pro life’. Substantiate the statement with suitable example. (MARCH-2014)
Answer:
Penicillin was widely used to kill bacteria during infection.
During second world war,it was widely used to treat soldiers against bacterial infection
Question 9.
In our state waste managenfient is a problem. Government promotes and give subsidy to Biogas plants. Comment the functioning of biogas plants with the help of microbes. (MAY-2014)
Answer:
Methanobacterium is used to produce biogas and can be used as source of energy as it is inflammable. It is an anaerobic bacterium used in sludge digesters.
Question 10.
Microbes can also be used as a source of energy. (MARCH-2015)
Substantiate with suitable examples.
Answer:
Methanobacterium is used to produce biogas and can be used as source of energy as it is inflammable.
Question 11.
BOD of some water samples are given below: (MAY-2015)
A. Sample 1 – 200 mg/L
B. Sample 2 – 80 mg/L
C. Sample 3 – 300 mg/L
D. Sample 4 – 25 mgIL
a) Which of the above water sample is most polluted?
b) What is meant by floes ? What is its role in sewage treatment?
Answer:
a) Sample 4
b) Floes- masses of bacteria associated with fungal filaments to form mesh like structures.
They consume the major part of the organic matter in the effluent. This is significantly reduces the BOD of the effluent.
Question 12.
“BOD is commonly calculated as an index of water pollution”. (MARCH-2016)
a) Do you agree with this statement? Why?
b) Expand BOD.
Answer:
a) Yes, if pollution load increases ,BOD increases
b) biochemical oxygen demand
Question 13.
Choose the correct answer from the bracket. (MAY-2016)
Cyclosporin A is produced by ______
a) Aspergellus
b) Clostridium
c) Trichoderma
d) Acetobacter
Answer:
Trichoderma
Question 14.
Select a bio-control agent from the given microbes: (MAY-2016)
a) Baculo virus
b) Rhino virus
c) Picrona virus
d) Adenovirus
Answer:
a) Baculovirus
Question 15.
Complete the table by filling A, B, C and D using hints from the bracket: (MAY-2017)
(Gobargas, Biological Control, Anabaena, Saccharomyces cerevisiae, Propionibacterium
sharmanii)
Answer:
A -Gobargas
B – Saccharomyces cerevisiae
C – Anabaena
D-Biological control